An apparatus and method of adaptively controlling a flying height of a magnetic head above a disk in accordance with a change in a user environment of a disk drive apparatus includes determining if a parameter reset condition related to the flying height of the magnetic head has been set; measuring a temperature of a disk drive if the parameter reset condition has been set, obtaining a flying height profile representing a variation of spacing between the magnetic head and a disk in accordance with a variation of power supplied to a heater controlling the flying height of the magnetic head at the measured temperature, based on a reference flying height profile stored in the disk drive, and determining the power that is to be supplied to the heater of the magnetic head, the power corresponding to a target flying height of the magnetic head from the obtained flying height profile.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method of adaptively controlling a flying height of a magnetic head, the method comprising: determining if a parameter reset condition related to the flying height of the magnetic head has been set; measuring a temperature of a disk drive if the parameter reset condition has been set; obtaining a flying height profile to represent a variation of spacing between the magnetic head and a disk according to a variation of power supplied to a heater to control the flying height of the magnetic head at the measured temperature; and determining the power that is to be supplied to the heater of the magnetic head, the power corresponding to a target flying height of the magnetic head from the obtained flying height profile.
2. The method of claim 1 , wherein the parameter reset condition comprises a condition in which the disk drive into an idle mode.
3. The method of claim 1 , wherein the flying height profile is obtained in a read mode and a write mode, respectively.
4. The method of claim 1 , wherein the obtaining of the flying height profile comprises; searching a reference flying height profile for a temperature closest to the measured temperature from among temperatures of flying height profiles stored in the disk drive apparatus, and calculating a temperature difference between the measured temperature and the temperature of the searched flying height profile; comparing the calculated temperature difference with an initially set threshold value; re-measuring the flying height profile of the magnetic head with respect to the measured temperature if the calculated temperature difference exceeds the threshold value, and storing the re-measured flying height profile; and obtaining a normalized flying height profile with respect to the measured temperature from among the flying height profiles stored in the disk drive if the calculated temperature difference does not exceed the threshold value.
5. The method of claim 4 , wherein the re-measuring of the flying height profile comprises: measuring a variation of spacing between the magnetic head and the disk with respect to the power supplied to the heater of the magnetic head, while varying the power supplied to the heater until the magnetic head contacts the disk; and obtaining the flying height profile with respect to the measured temperature.
6. The method of claim 5 , wherein the variation of the spacing between the magnetic and the disk is obtained using a Wallace spacing loss equation.
8. The method of claim 4 , wherein the normalized flying height profile is obtained based on a correction value with respect to the variation of temperature in the flying height profile of the temperature closest to the measured temperature from among the flying height profiles stored based on temperature in the disk drive.
9. The method of claim 4 , wherein the normalized flying height profile is obtained by interpolation between the flying height profiles at uppermost and lowermost temperatures closest to the measured temperature from among the flying height profiles stored in the disk drive.
10. A computer-readable recording medium on which a computer-executable program is recorded, the computer-executable program comprising: determining if a parameter reset condition related to the flying height of the magnetic head has been set; measuring a temperature of a disk drive if the parameter reset condition has been set; obtaining a flying height profile representing a variation of spacing between the magnetic head and a disk in accordance with a variation of power supplied to a heater controlling the flying height of the magnetic head at the measured temperature, based on a flying height profile stored in the disk drive; and determining the power that is to be supplied to the heater, and the power corresponding to a target flying height of the magnetic head from the obtained flying height profile.
11. A disk drive comprising: a disk to store data; a magnetic head comprising: a magnetic read element to detect a magnetic field over the disk; a magnetic write element magnetize the disk; and a heater configured to generate an air bearing surface between a surface of the disk and the magnetic read element and between the surface of the disk surface and the magnetic write element, the heater to heat a structure generate the air bearing surface; a temperature sensor to measure an operating temperature of the disk drive; a memory to store the measured temperature and a flying height profile representing a variation of spacing between the magnetic head and the disk in accordance with a variation of power supplied to the heater; a controller to calculate the flying height profile to represent the variation of the spacing between the magnetic head and the disk in accordance with the variation of the power supplied to the heater at the temperature measured by the temperature sensor, based on a reference flying height profile stored in the memory, if the parameter reset condition related to the flying height of the magnetic head has been set, and determining the power that is to be supplied to the heater corresponding to a target flying height of the magnetic head from the calculated flying height profile; and a current supplier to generate a current corresponding to the power determined by the controller and supplying the generated current to the heater.
12. The disk drive of claim 11 , wherein the parameter reset condition related to the flying height of the magnetic head comprises a condition so as to change the disk drive into an idle mode.
13. The disk drive of claim 11 , wherein the flying height profile is obtained in a read mode and a write mode respectively.
14. The disk drive of claim 11 , wherein the controller searches from the memory the reference flying height profile having a temperature closest to the temperature measured by the temperature sensor, re-measures the reference flying height profile with respect to the measured temperature to store the re-measured flying height profile in the memory as the flying height profile if a temperature difference between the measured temperature and the temperature of the searched flying height profile exceeds a threshold value, and calculates a normalized flying height profile with respect to the measured temperature from the flying height profile stored based on temperature in the disk drive apparatus if the temperature difference does not exceed the threshold value.
15. The disk drive of claim 14 , wherein the controller measures a variation of spacing between the magnetic head and the disk with respect to a variation of the power supplied to the heater, while varying the power supplied to the heater controlling the flying height of the magnetic head until the magnetic head contacts the disk, and obtains the flying height profile with respect to the measured temperature.
16. The disk drive of claim 15 , wherein the controller calculates the variation of the spacing between the magnetic and the disk using a Wallace spacing loss equation.
17. The disk drive of claim 14 , wherein the controller calculates a normalized flying height profile based on a correction value with respect to the variation of temperature in the flying height profile of the temperature closest to the measured temperature from among the flying height profiles stored based on temperature in the memory.
18. The disk drive of claim 14 , wherein the controller calculates the normalized flying height profile by interpolation between the flying height profiles at uppermost and lowermost temperatures closest to the measured temperature from among the flying height profiles stored in the memory.
19. An apparatus to control a flying height of a magnetic head from a disk in a disk drive apparatus, comprising: a controller to supply a current to a heater of the disk drive apparatus using a flying height profile to generate a spacing between a magnetic head and a disk; and a temperature sensor to measure a temperature of the disk drive apparatus wherein the controller obtains a new flying height profile from a reference flying height profile according to the temperature measured by the temperature sensor.
20. The apparatus of claim 19 , further comprising: a memory unit disposed in the disk drive apparatus to store the obtained flying height profile.
21. The apparatus of claim 19 , wherein the controller controls the heater of the disk drive apparatus according to the obtained flying height profile.
22. The apparatus of claim 19 , wherein: the obtained flying height profile comprises a first flying height profile to correspond to a read mode, and a second flying height profile to correspond to a write mode; and the controller controls the heater according to a first current and a second current of the first flying height profile and the second flying height profile in the read mode and the write mode, respectively, to maintain a same target flying height of the spacing in the read mode and the write mode.
23. The apparatus of claim 19 , wherein: the controller supplies the current according to a reference flying height profile including a plurality of current values to be supplied to the heater, and a plurality of temperatures, and the controller selects one of the current values as the current to be supplied to the heater.
24. A disk drive apparatus to control a flying height of a magnetic head from a disk, comprising: a temperature sensor to detect a temperature of the disk drive apparatus; a memory unit to store a reference flying height profile and a new flying height profile modified from the reference flying height profile according to a temperature variance of the detected temperature of the temperature sensor; and a controller to supply a current to a heater according to the detected temperature and the new flying height profile.
25. A disk drive apparatus to control a flying height of a magnetic head from a disk, comprising: a memory unit to store a flying height profile having a plurality of temperatures and current values to correspond to the respective temperatures; a temperature sensor to detect a current temperature of the disk drive apparatus; and a controller to supply a current to a heater according to one of the current values of the new flying height profile to correspond to the detected temperature.
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April 7, 2008
June 14, 2011
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